Adsorption of human serum albumin on electrochemical titanium dioxide electrodes: Protein?oxide surface interaction effects studied by electrochemical techniques

FABIANA Y. OLIVA; OSVALDO R. CÁMARA; LUCÍA B. AVALLE

Elsevier

Año: 2009 vol. 633 p. 19 - 19

The adsorption of Human Serum Albumin (HSA) on a semiconductor TiO2 electrochemical oxide was investigated using Cyclic Voltammetry (CV), Capacity?Potential curves (C?E) and time-resolved techniques as a function of electrode potential and protein concentration. The presence of HSA adsorbed on the electrode surface modifies the voltamperometric behavior of the hydrogen evolution reaction (her) and also produces a major modification in the diffusional layer thickness of the H+ ions. The adsorbed amounts of HSA were analyzed throughout different adsorption isotherms. The experimental data were modeled with a modified Langmuir type isotherm, considering a weak chemisorption on a surface with heterogeneity in site-energy distribution with some degree of attractive lateral interactions between the adsorbed protein molecules. The effect of the adsorption potential (Eads) was investigated polarizing the electrode at 0.70, 0.50 and 0.08 V vs. SCE. The capacity response obtained from the diff